Added more _exclusive() functions with no atomic operations. Start adding Ref, that tracks a single slot.

Fixed partial iterstor"s size_hint() not updating when the iterator is consumed.

Fortune for parapop's current commit: Future small blessing − 末小吉

src/.#iter.rs

@@ -0,0 +1 @@
+avril@eientei.11314:1642638923

src/iter.rs

@@ -33,10 +33,13 @@ impl<T> PartialIter<T> {
 	let a = self.0.next()?;
 	let b = if cfg!(debug_assertions) { self.1.next()? } else { unsafe { self.1.next().unwrap_unchecked() } };
 
+	self.2-=1;
 	Some((a, b.into_inner()))
     }
 }
 
+
+
 impl<T> Iterator for PartialIter<T>
 {
     type Item = T;
@@ -117,7 +120,7 @@ unsafe fn assume_init_boxed<T>(bx: Box<[MaybeUninit<T>]>) -> Box<[T]>
 
 impl<'a, T> IntoIter<'a, T>
 {
-    pub(super) fn create_from(mut pop: Populator<T>) -> Self
+    pub(super) fn create_from(mut pop: Populator<'a, T>) -> Self
     {
 	Self(if pop.is_full_exclusive() {
 	    let values = pop.take_values();
@@ -146,3 +149,29 @@ impl<'a, T> Iterator for IntoIter<'a, T>
 }
 impl<'a, T> FusedIterator for IntoIter<'a, T>{}
 impl<'a, T> ExactSizeIterator for IntoIter<'a, T>{}
+
+#[derive(Debug)]
+struct FullIterRef<'a, T>(std::slice::Iter<'a, T>);
+
+impl<'a, T> Iterator for FullIterRef<'a, T>
+{
+    type Item = &'a T;
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+	self.0.next()
+    }
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	self.0.size_hint()
+    }
+}
+
+impl<'a, T> DoubleEndedIterator for FullIterRef<'a, T>
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+	self.0.next_back()
+    }
+}
+
+impl<'a, T> FusedIterator for FullIterRef<'a, T>{}
+impl<'a, T> ExactSizeIterator for FullIterRef<'a, T>{}

src/lib.rs

@@ -6,12 +6,25 @@ use std::sync::atomic::{
     AtomicBool,
     AtomicUsize,
 };
+use std::cmp::Ordering;
 use std::mem::{self, MaybeUninit};
 use std::cell::UnsafeCell;
 use std::ops::Drop;
 
 pub mod iter;
-use iter::*;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Default, Copy)]
+#[repr(transparent)]
+struct PhantomLifetime<'a>(std::marker::PhantomData<&'a ()>);
+
+impl<'a> PhantomLifetime<'a>
+{
+    #[inline(always)]
+    pub const fn new() -> Self { Self (std::marker::PhantomData) }
+}
+
+unsafe impl<'a> Send for PhantomLifetime<'a>{}
+unsafe impl<'a> Sync for PhantomLifetime<'a>{}
 
 mod private
 {
@@ -19,14 +32,71 @@ mod private
 }
 
 /// A parallel, atomic populator of items
-pub struct Populator<T>
+#[derive(Debug)]
+pub struct Populator<'a, T: 'a>
 {
     values: UnsafeCell<Box<[MaybeUninit<T>]>>,
     populates: Box<[AtomicBool]>, // 
     populated: AtomicUsize, // number of populated items
+
+    _lt: PhantomLifetime<'a>,
 }
 
-impl<T> Populator<T>
+#[derive(Debug)] // PartialEq, PartialOrd
+pub struct Ref<'re, 'a, T: 'a>
+{
+    pop: &'re Populator<'a, T>,
+    idx: usize,
+    //TODO: Maybe add inserted bool, or state representing if this Ref has made a change to the populator. The value will be loaded on creation of the Ref, and will be used as a cached version of `completes[idx].load()`
+    //TODO:   OR: Hold a reference to the actual AtomicBool at `idx` itself?
+}
+
+#[inline(always)]
+unsafe fn address_eq_overlap<'t, 'u, T, U>(a: &'t T, b: &'u U) -> bool
+{
+    std::ptr::eq(a as *const _, b as *const _ as *const T)
+}
+#[inline(always)]
+fn address_eq<'a, 'b, T: ?Sized>(a: &'a T, b: &'b T) -> bool
+{
+    std::ptr::eq(a as *const _, b as *const _)
+}
+
+impl<'re, 'a, T: 'a> PartialEq for Ref<'re, 'a, T>
+{
+    #[inline]
+    fn eq(&self, other: &Self) -> bool
+    {
+	address_eq(self.pop, other.pop) && self.idx == other.idx
+    }
+}
+
+impl<'re, 'a, T: 'a> PartialOrd for Ref<'re, 'a, T>
+{
+    #[inline]
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+	if address_eq(self.pop, other.pop) {
+	    self.idx.partial_cmp(&other.idx)
+	} else {
+	    None
+	}
+    }
+}
+
+impl<'re, 'a, T: 'a> Ref<'re, 'a, T>
+{
+    /// Checks if the references item currently exists.
+    #[inline]
+    pub fn exists(&self) -> bool
+    {
+	self.pop.exists(self.idx)
+    }
+    //TODO: Rest, including insertions, etc.
+}
+
+//TODO: RefEx: Exclusive reference, holds &'ref mut Populator<'a, T>
+
+impl<'a, T: 'a> Populator<'a, T>
 {
     #[inline(always)]
     fn values_mut(&mut self) -> &mut [MaybeUninit<T>]
@@ -53,7 +123,7 @@ impl<T> Populator<T>
     }
 }
 
-impl<T> Drop for Populator<T>
+impl<'a, T> Drop for Populator<'a, T>
 {
 
     fn drop(&mut self)
@@ -84,18 +154,41 @@ impl<T> Drop for Populator<T>
     }
 }
 
-unsafe impl<T> Send for Populator<T> where Box<T>: Send {}
-unsafe impl<T> Sync for Populator<T>{} // Populator is always sync
+unsafe impl<'a, T: 'a> Send for Populator<'a, T> where Box<T>: Send {}
+unsafe impl<'a, T: 'a> Sync for Populator<'a, T>{} // Populator is always sync
 
-impl<T> Populator<T>
+impl<'a, T> Populator<'a, T>
 {
-    
+    /// Checks if an item exists at this index exclusively.
+    ///
+    /// Since this is an exclusive reference, no atomic operations are performed.
+    #[inline]
+    pub fn exists_exclusive(&mut self, idx: usize) -> bool
+    {
+	*self.populates[idx].get_mut()
+    }
+    /// Checks if an item exists currently at this index.
+    #[inline]
+    pub fn exists(&self, idx: usize) -> bool
+    {
+	self.populates[idx].load(atomic::Ordering::SeqCst)
+    }
+    /// How many items are populated
+    ///
+    /// Faster access as this is an exclusive reference and no atomic operations are needed
+    #[inline]
+    pub fn populated_exclusive(&mut self) -> usize
+    {
+	*self.populated.get_mut()
+    }
+    #[inline]
     /// How many items are populated
     pub fn populated(&self) -> usize
     {
 	self.populated.load(atomic::Ordering::Acquire)
     }
     /// Is the populator full?
+    #[inline]
     pub fn is_full(&self) -> bool
     {
 	self.populated() == self.len()
@@ -106,6 +199,16 @@ impl<T> Populator<T>
     {
 	self.values_ref().len()
     }
+    
+    /// Number of items held by the populator
+    ///
+    /// A faster access than normal `len()`, since this is an exclusive reference 
+    #[inline]
+    pub fn len_exclusive(&mut self) -> usize
+    {
+	self.values.get_mut().len()
+    }
+    
     /// Create a new, empty populator with this size
     pub fn new(size: usize) -> Self
     {
@@ -118,6 +221,8 @@ impl<T> Populator<T>
 	    }.into_boxed_slice()),
 	    populates: std::iter::repeat_with(|| false.into()).take(size).collect(),
 	    populated: 0usize.into(),
+
+	    _lt: PhantomLifetime::new(),
 	}
     }
 
@@ -154,10 +259,43 @@ impl<T> Populator<T>
 	}
     }
 
+    /// Get a reference to an item at `idx` whether it exists or not.
+    #[inline]
+    pub fn get_ref(&self, idx: usize) -> Ref<'_, 'a, T>
+    {
+	Ref {
+	    pop: self,
+	    idx
+	}
+    }
+
+    /// Try to get an exclusive, mutable reference to an item at `idx` if an item exists there.
+    ///
+    /// No atomic operations are performed since this is an exclusive reference.
+    #[inline]
+    pub fn try_get_exclusive_mut(&mut self, idx: usize) -> Option<&mut T>
+    {
+	if *self.populates[idx].get_mut() {
+	    Some(unsafe{ self.values.get_mut()[idx].assume_init_mut() })
+	} else {
+	    None
+	}
+    }
+
+    /// Try to get an exclusive, mutable reference to an item at `idx` if an item exists there.
+    ///
+    /// No atomic operations are performed since this is an exclusive reference.
+    #[inline]
+    pub fn try_get_exclusive(&mut self, idx: usize) -> Option<&T>
+    {
+	self.try_get_exclusive_mut(idx).map(|&mut ref a| a)
+    }
+
     /// Insert `value` into `idx`.
     ///
     /// # Panics
     /// If `idx` already has a value inserted.
+    #[inline] // Maybe?
     pub fn insert(&self, idx: usize, value: T) -> usize
     {
 	#[inline(never)]
@@ -215,6 +353,7 @@ impl<T> Populator<T>
     ///
     /// # Panics
     /// If the collection is not fully populated.
+    #[inline] // Maybe?
     pub fn complete(self) -> Box<[T]>
     {
 	#[inline(never)]
@@ -231,10 +370,31 @@ impl<T> Populator<T>
     }
 }
 
-impl<T: 'static> IntoIterator for Populator<T> // FUCK why do we need to make this 'static???? fuck this... dyn dispatch in rust is so jank. why can't we use 'a!!!
+impl<'a, T: 'a> FromIterator<Option<T>> for Populator<'a, T>
+{
+    fn from_iter<I: IntoIterator<Item = Option<T>>>(iter: I) -> Self {
+	let mut v =0usize;
+	let (items, bools) : (Vec<_>, Vec<AtomicBool>) = iter.into_iter()
+	    .map(|x| x.map(|item| { v +=1; (MaybeUninit::new(item), true.into()) })
+		 .unwrap_or((MaybeUninit::uninit(),false.into())))
+	    .unzip();
+	
+	debug_assert_eq!(items.len(), bools.len(), "invalid ");
+
+	Self {
+	    populated: v.into(),
+	    values: UnsafeCell::new(items.into_boxed_slice()),
+	    populates: bools.into_boxed_slice(),
+	    
+	    _lt: PhantomLifetime::new(),
+	}
+    }
+}
+
+impl<'a, T: 'a> IntoIterator for Populator<'a, T> // FUCK why do we need to make this 'static???? fuck this... dyn dispatch in rust is so jank. why can't we use 'a!!!
 {
     type Item = T;
-    type IntoIter = iter::IntoIter<'static, T>;
+    type IntoIter = iter::IntoIter<'a, T>;
     
     #[inline]
     fn into_iter(self) -> Self::IntoIter {